This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. Two sets of new experiments began during the last year. 1. The task-dependence of the output effects of intraspinal stimulation are being investigated. A monkey was trained on a wrist task and a reach-and-grasp task, and muscle and nerve electrodes were implanted;a vertebral device will be implanted soon. Electrical stimuli will be delivered to the intermediate and ventral laminae of the cervical spinal cord as the animal performs the trained tasks. Differences in the responses of arm muscles during the different tasks will elucidate features of spinal organization controlling voluntary limb movements. 2. Initial recording in the external cuneate nucleus are underway. This study will examine the properties of neurons relaying proprioceptive information from the arm and hand to the cerebellum during voluntary movements. In collaboration with data collected by Dr. Yifat Prut (Hebrew University, Jerusalem, Israel), we will elucidate the type of information carried by spinocerebellar pathways during normal behavior. In addition, a new series of experiments on the responses of cervical spinal interneurons to perturbations of the wrist and hand is being set up. The Primate Center Bioengineering Core is constructing a new apparatus for use in these experiments and an animal is being trained. We hope to start these experiments during the next year.